What cause astigmatism?

What causes astigmatism?
And will glasses help to correct astigmatism?
Or time will heal by itself?

[James J Salz, M.D.]

Unfortunatelly the word "astigmatism" (stigmata of Christ) sonds more serious than just being nearsighted or farsighted but it really is not. In most cases, astigmatism is cause by a cornea that is not round like a ball but shaped more like football or teaspoon so there is a long flatter curve and a steeper curve.  These 2 curatures are 90 degrees apart and are correctable by spectale lense or contact lenses.  In reality, most nearsighted and farsighted eyes also have some astigmatism. The glasses or contact lenses do not cure the astigmatism, they merely correct it while the glasses or contacts are worn.  The only way to "correct" it is with Laser eye surgery which can correct most cases of astigmatism for patients who dislike wearing glasses or contact lenses.

[Nancy T]

Is it true that astigmatism can come and go? I seem to remember that my (ex-)optometrist would sometimes say that my astigmatism had gotten better or worse from one year to the next.

What can make the cornea change shape? Do you believe it can happen very quickly though transiently, such as from having the eyelids down, as when reading something in your lap?

Nancy T.

[edensgreen]

A related discussion, Pterygium removed was started.